1612097 - Provide API to cancel WebExtensionController.install

Status: RESOLVED FIXED

(GeckoView :: Extensions, enhancement, P1)

Description

[Christian Sadilek [:csadilek]]

This is so Fenix can display a cancel option while installing add-ons.

Comment 1

[James Willcox (:snorp) ([e-mail]) (he/him)]

There are a couple ways to do this, but I think perhaps the most generally useful way would be to introduce a new GeckoCancelableResult, and return that from install(). It would look something like:

public abstract class GeckoCancelableResult extends GeckoResult {
    public GeckoResult<boolean> cancel();
}

The semantics are where things get tricky, but I think we should try to be close to CompletableFuture here. After all, we'd probably be using that directly if we could. CompletableFuture#cancel()[1] causes the future to be completed with a CancelationException if it has not already been completed. So a more complete impl would look like:

public abstract class GeckoCancelableResult extends GeckoResult {
    public GeckoResult<boolean> cancel() {
        completeExceptionally(new CancelationException());
        return GeckoResult.fromValue(true);
    }
}

I think we should keep this class abstract so we don't have cancel() methods that are noops that appear to succeed. We'll then need subclasses for individual cancelable operations, and the subclass would return super.cancel() once they had completed the work necessary to cancel the operation. Nothing stops someone from doing super.cancel() directly, I guess, but at least they will feel bad.

[1] https://docs.oracle.com/javase/8/docs/api/java/util/concurrent/CompletableFuture.html#cancel-boolean-

Comment 2

[Thomas Wisniewski [:twisniewski]]

Unfortunately, the subclass approach in comment 1 won't be pretty, because GeckoResult internally instantiates GeckoResults (not the correct subclass) when calling methods like then. As such, snorp and I decided to just add a cancel method to GeckoResult for now and prevent that mess.

Comment 3

[Thomas Wisniewski [:twisniewski]]

Attachment: Summary: Add a .cancel() method to the promise returned by WebExtensionResult.install

Comment 4

[Thomas Wisniewski [:twisniewski]]

After quite a bit of back-and-forth with snorp, we've decided that using GeckoResult in this way just isn't tenable right now; it's not really designed to be used this way. For now, we'll just add a WebExtensionController.cancelInstall method which accepts the GeckoResults returned by .install(). A try-run of this approach seems fine: https://treeherder.mozilla.org/#/jobs?repo=try&revision=a948dbf2bfd9c6d73d56984b685b2074583e54b0

Comment 5

[Thomas Wisniewski [:twisniewski]]

Attachment: Bug 1612097 - Add ability to cancel the GeckoResult returned by WebExtensionControll.install(BuiltIn); r?snorp,r?agi!

add WebExtensionController.cancelInstall(GeckoResult<WebExtension>), accepting the GeckoResults returned by .install()

Comment 6

[James Willcox (:snorp) ([e-mail]) (he/him)]

Attachment: Bug 1612097 - Add GeckoResult.cancel()

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/48d5409e907b
Add GeckoResult.cancel() r=geckoview-reviewers,agi,esawin

Comment 8

[James Willcox (:snorp) ([e-mail]) (he/him)]

Only part of this has landed, so adding leave-open

Comment 9

[Natalia Csoregi [:nataliaCs]]

https://hg.mozilla.org/mozilla-central/rev/48d5409e907b

Comment 10

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/79c33a0692de
Add ability to cancel the GeckoResult returned by WebExtensionControll.install(BuiltIn); r=snorp,agi

Comment 11

[Daniel Varga [:dvarga]]

https://hg.mozilla.org/mozilla-central/rev/79c33a0692de